While Washington debates farm subsidies and trade policy, a proven Canadian technology is turning toxic mine waste into commercial-grade ammonium sulphate fertiliser — from geopolitically stable countries whose stockpiles could never be sanctioned, blockaded, or withheld.

By Tim Lewin, Chairman, BacTech Environmental Corporation

American farmers are facing their third major fertiliser supply shock in a decade. Russian export restrictions in 2022, natural gas price spikes in 2023, and now the disruption to Persian Gulf shipping lanes have repeatedly exposed the same structural vulnerability: the United States imports a substantial share of its nitrogen fertiliser from a small number of exporters concentrated in geopolitically unstable or adversarial regions. Every time a crisis hits, fertiliser prices spike, planting decisions get harder, and food prices follow.

Washington’s response has been predictable — emergency waivers, diplomatic calls, subsidy programmes. Each one addresses the symptom. None addresses the cause. The cause is simple: the US fertiliser supply chain is built on a foundation of fossil fuels, foreign dependence, and maritime chokepoints that can be closed without warning.

There is a better answer. It does not require new legislation, new trade agreements, or new natural gas infrastructure. It requires looking at a resource that already exists in vast quantities, in the US and its closest ally Canada, sitting above ground in mining communities from Ontario to Montana to Arizona. It is currently classified as waste. It should be classified as a strategic asset.

The Resource America Is Standing On

Across North America, decades of copper, nickel, zinc, and gold mining have left behind hundreds of millions of tonnes of sulphide-bearing tailings — the residual waste from ore processing operations. In Sudbury, Ontario alone, there are more than 70 million tonnes of pyrrhotite tailings at approximately 45 per cent sulphide content. Similar stockpiles exist across Michigan, Montana, Arizona, Nevada, and the broader western United States — stable, rule-of-law jurisdictions whose mineral waste cannot be sanctioned, blockaded, or subjected to export restrictions by a foreign government.

These tailings are not passive. They generate acid mine drainage, require perpetual environmental monitoring, and impose ongoing remediation liabilities on the operators who own them. They are, in accounting terms, a liability. In strategic terms, they are an untapped fertiliser feedstock of extraordinary scale.

BacTech Environmental Corporation’s patented Zero-Tailings™ process converts sulphide-bearing mine tailings directly into ammonium sulphate fertiliser — a widely used nitrogen source for cereals, oilseeds, vegetables, and acidic or sulphur-deficient soils across the American Midwest and South. The Sudbury pyrrhotite tailings alone could yield in the order of 25 million tonnes of ammonium sulphate. Canada currently runs an annual fertiliser trade deficit of approximately C$60 million. The US deficit is considerably larger.

Proven Technology, Real Product

This is not a speculative proposition. BacTech’s core BacOx bioleaching technology — in which naturally occurring bacteria oxidise sulphide minerals, producing a sulphaterich process stream and liberating trapped minerals for recovery. In April 2025, BacTech filed a patent to produce crystalline ammonium sulphate and magnetite from the pregnant liquor when combined with an ammonia source. The original BACOX technology has been independently rated by Moody’s as ‘very good’ for social and environmental benefit.

The Zero-Tailings™ application of this technology has now produced commercialgrade ammonium sulphate and magnetite from real pyrrhotite tailings at the pilot facility operated by Mirarco at Laurentian University in Sudbury — with independent laboratory validation of product quality underway. The research programme has attracted funding from Natural Resources Canada’s Critical Minerals Research, Development and Demonstration programme, the Ontario Centre of Innovation, and industrial support from Vale Base Metals, one of the world’s largest nickel producers.

The process flowsheet has recently been strengthened by the addition of Reverse Osmosis pre-concentration and Mechanical Vapour Recompression evaporation technologies, both commercially established in industrial applications, which reduce energy consumption and support consistent production of specification-grade fertiliser product. The complete flowsheet — from acidic waste stream through to saleable ammonium sulphate — is now covered by an updated provisional patent application.

The Supply Chain America Needs

The geopolitical argument for mine-waste-derived fertiliser is straightforward. The countries that hold the largest sulphide tailings inventories are, almost without exception, stable democracies with strong property rights, transparent legal systems, and no history of weaponizing commodity exports. The United States, Canada, Australia, Chile — these are not countries that impose surprise export quotas, redirect supply to preferred trading partners, or close shipping lanes. Their mine waste stockpiles are immune to the kind of geopolitical disruption that has repeatedly cascaded into American food price crises.

The feedstock, moreover, is not scarce. Sulphide-bearing tailings run into the billions of tonnes globally, with significant volumes in the continental United States itself. New tailings are generated every year as mining continues. A fertiliser supply chain built on this feedstock would be domestic or near-domestic, fossil-fuel independent, and structurally insulated from the vulnerabilities that have made American agriculture hostage to Russian export policy and Persian Gulf shipping.

There is an additional dimension that should interest the current administration specifically. Mine tailings represent one of the most significant unfunded environmental liabilities in the American West. Operators are required to post financial assurance — bonds, letters of credit, cash deposits — against the eventual cost of remediation. Technologies that convert reactive sulphide tailings into commercial products reduce those liabilities, free up capital, and accelerate the clean-up of mining’s environmental legacy without requiring federal expenditure. Economic development and environmental remediation, for once, are not in tension.

What Comes Next

The Zero-Tailings™ process is at the scale-up stage. The chemistry is proven. The pilot product is real. Independent validation of commercial-grade quality is in progress. The next step is the translation of proven bench and pilot-scale results into a full-scale demonstration plant — a step that requires capital, industrial partnerships, and the engagement of operators who understand their own tailings liabilities and can see the commercial logic of converting them into a revenue stream.

American mining companies operating in sulphide-rich regions — Arizona copper, Nevada gold, Michigan nickel, Montana silver — are sitting on exactly the feedstock this process requires. American fertiliser distributors are watching import prices spike again. American farmers are making planting decisions under input cost uncertainty that a domestic, geopolitically stable supply source would permanently resolve.

The solution to America’s fertiliser vulnerability is not in the Persian Gulf, or in Moscow, or in a new natural gas pipeline. It is in the tailings piles of the American and Canadian West, waiting to be recognised for what they are: not a liability, but a strategic resource. The technology to unlock them exists, has been proven, and is ready to scale.

The only question is whether the mining industry, the fertiliser sector, and the policymakers who care about American food security will move quickly enough to seize it.

The author is Chairman of BacTech Environmental Corporation (CSE: BAC | OTCQB: BCCEF), a Canadian clean-technology company specialising in the commercialisation of bioleaching and advanced mineral processing technologies. BacTech’s Zero-Tailings™ platform is being developed in partnership with Mirarco at

Laurentian University, Sudbury, with support from Natural Resources Canada, Vale Base Metals, and the

Ontario Centre of Innovation. The underlying bioprocessing technology has been independently rated by Moody’s as ‘very good’ for social and environmental benefit, and has been deployed in licensed operating plants in Australia and China.